How to use resin cements to bond indirect restorations
When it comes to indirect restorations, using resin cements can help maximize bond strength, increase predictability and decrease stress.
Recent advancements in dental materials have created “smart cements” indicating the ideal time for cement removal. This allows for easy cleanup, better chance of sealed margins and improved clinical success.
The delivery of indirect restorations has changed substantially over the years as new materials have come to market. Resin cements have been used for bonding leucite reinforced ceramic materials since the late 80s. During those first 20 years, resin cement use was limited to cosmetic procedures that were not done on a routine basis so the process was often confusing to dentists. 2006 is when we noticed a change, as lithium disilicate reemerged on the market as a partially crystalized milling block used for CEREC restorations. The flexural strength was 170 percent higher than any other ceramic at that time so it became wildly popular as both an anterior and posterior solution for restoring teeth.
In 2010, full-contour zirconia became more popular and along with eMAX influenced dentists to use less PFM and gold, and to start using more all ceramic crowns. This shift influenced the dental labs to do the same and the dental material manufacturers started leaning away from metal alloy-containing restoratives and favoring all-ceramic restorative dentistry.
While all these changes were happening with restorative materials, we also started seeing changes in the way we were bonding our restorations. The total-etch technique was the most common at the time. It is technique sensitive, and if not done correctly, patients can experience lasting post-op sensitivity with their restorations or they can develop stained margins if not sealed correctly. Because of this, we saw the introduction of more self-etch/self-adhesive cements like Maxcem and Unicem and dual cure cements like NX3/XTR from Kerr and Multilink from Ivoclar. These cements do not require etching of the tooth with phosphoric acid. The self-etch/self-adhesive cements use nothing on the tooth when the restoration is seated and the dual-cure cements use a self-etching primer and adhesive that is applied to the tooth and air thinned. The restoration is filled with the dual-cure cement and seated.
We saw much less post-op sensitivity with these methods, but we saw increased incidence of residual cement being left between the teeth and it wasn’t uncommon to accidentally bond teeth together during the process. At that time, NX3/XTR started to grow in the market because doctors could get all the benefits of a dual cure resin cement but also have easy clean up too.
Kerr recently announced the release of their Maxcem Elite Chroma resin cement. It is a self-etch, self-adhesive resin cement with a cleanup indicator. Translation: it is a low-sensitivity, easy-to-use resin cement that takes all the guesswork out of the cleanup process. It makes the last five minutes of the appointment stress free and predictable.
Continue to the next page to see how Maxcem Elite Chroma was used to treat two recent cases.